The preparation of pyrimidines and 2-alkylpyrimidines by the reaction of an alkylene 1,3-diamine with an organic carboxylic acid, ester or amide over a supported noble metal catalyst is taught in U.S. Pat. No. 3,050,523. This reference teaches the cyclization of, for example, an organic carboxylic acid amide followed by dehydrogenation. The steps of the work-up and separation of product by the method taught in this reference are time consuming and cumbersome and the resulting yields are not commercially attractive.